Our proposed research concerns the pathways of drainage of canine pulmonary lymph. We have developed a method for the collection of pure pulmonary lymph by cannulation of hilar lymphatic. With pure pulmonary lymph we can improve the data used to estimate pulmonary vascular water balance in the canine model. We also propose to investigate the pathways of drainage of pulmonary lymph from the lower lobes of the right and left lung to the right lymphatic duct (RD) and thoracic duct (TD). For this purpose we are using LDH and SGOT levels in RD and TD lymph before and after serially subjecting the lower lobes to mild trauma. We also wish to investigate the contribution of lung lymph to the RD and TD by repeating the above experiments in dogs in which the TD has been obstructed above the diaphragm by ligature.